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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The determination of the reactivity of the histidine residues of sperm whale met-myoglobin with bromoacetate

Andrews, Patricia Amanda January 1964 (has links)
This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).
12

Carboxymethyl and azo derivatives of histidine

Hapner, Kenneth Dale January 1966 (has links)
This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).
13

Contributions à la compréhension des phénomènes de nucléation induite par laser : applications à la glycine et études préliminaires sur l'histidine et l'acide glutamique / Contributions to the understanding of nucleation phenomena induced by laser : applications glycine and preliminary studies on histidine and glutamic acid

Clair, Bertrand 21 November 2014 (has links)
Le contrôle de la fabrication des structures cristallines des médicaments est un enjeu crucial pour l'industrie pharmaceutique. Plusieurs exemples ont montré qu'une mauvaise maîtrise du polymorphisme conduisait à des situations dramatiques. Récemment, une méthode permettant la maîtrise du polymorphisme de molécule organique dissoute en solution à l'aide de la polarisation d'un faisceau laser a été découverte aux Etats-Unis. Cette thèse étudie l’effet du laser sur des solutions aqueuses de molécules de glycine, L – (+) – histidine, D – (-) – et L – (+) – acide glutamique. Afin de réaliser l’étude, un montage expérimental a été construit permettant le contrôle de nombreux paramètres et une méthode spécifique de travail a été développée afin de limiter fortement l’aléa expérimental. Une étude multi-paramètres incluant l’effet comparé des polarisations linéaire et circulaire dans du H2O et du D2O de la nucléation induite par laser non-photochimique (NPLIN) de la glycine a été menée. Une étude préliminaire de l’effet du laser sur les solutions d'histidine et de l' acide glutamique a également été réalisée. Il est montré que le solvant est un facteur déterminant du contrôle du polymorphisme. Toutefois, la conjonction de la polarisation et de la concentration a une influence sur les polymorphes de glycine obtenus dans le H2O. Les résultats obtenus permettent de contribuer à la compréhension du mécanisme en améliorant l'hypothèse initiale de l'effet Kerr. / Polymorphism control of drug molecules is one the main challenges facing drug companies. Several examples have shown than an uncontrolled polymorphism crystallization could lead to dramatic situation. One the most recent progress in the polymorphism control is the unwanted discovery of polymorphic selective crystallization of organic molecule dissolved in solution based on the laser beam polarization. This thesis deals with the implantation of this method in France for the first time based on a methodology limiting experimental hazard and a special design experimental device dedicated to this study. This work is based on an important review of known results of the field and published for the first time. An important multifactor study was done on glycine, histidine and glutamic acid, which allows to improve knowledges on the putative initial mechanism based on the Kerr effect. It has been established that the solvent is the dominant factor, letting laser polarization as the third factor for polymorphism control after concentration.
14

Model studies of the cub-histidine-tyrosine centre in cytochrome c oxidase

Lee, Sang Tae, Chemistry, Faculty of Science, UNSW January 2005 (has links)
This thesis reports the synthesis and copper coordination chemistry of covalently-linked aryl-imidazole derivatives designed as models for the crosslinked imidazole-phenol sidechains of the His-Tyr cofactor in the CcO. Three new imidazole- (HL1 - HL3) and three new indole- (HL4 - H2L6) containing tripodal ligands were synthesised. The conjugate addition of an imidazole to activated quinone derivatives was developed as a new route to organic models for the Tyr His cofactor. Two monodentate imidazole-aryl, Im-hq(OH)2 and Im-ArOH, and an imidazole-quinone, Im bq were obtained using this route. The X-ray crystal structure of Im-hq(OH)2.EtOH was determined. The route was also used to give new chelating ligands, H2L10 and HL12, containing a cross-linked imidazole-phenol surrogate for the Tyr244-His240 cofactor. Copper complexes of Im-hq(OH)2, Im-bq, Im-ArOH, H2L10-HL12, and HL1-H2L6 were prepared, and the X-ray crystal structures of [Cu(terpy)(Im-bq)][BF4]2 and five other copper complexes were determined. The physiochemical properties of the copper complexes were characterized by FT-IR, UV-Vis-NIR, EPR and (spectro)electrochemical studies. Key results include: the oxidation of Im-ArO- anion affords the semiquinone radical, Im-sq(4OH)(1O??????), in a hydrous solvent. However, the oxidations of neutral Im-ArOH and [Cu(tpa)(Im-ArOH)]2+ produce the corresponding phenoxy radical species that rapidly and reversibly dimerise to give quinol cyclohexadienone, QCHD, dimers. Significantly [Cu(tpa)(Im-sq(4OH)(1O??????))]2+ was EPR silent, perhaps due to antiferromagnetic coupling between the Cu(II) (S=1/2) and semiquinonyl radical (S=1/2) centres. Deprotonation of the hydroquinone in [Cu(tpa)(Im-hq(OH)2]2+ produces the hydroquinone dianion which reduces the Cu(II) centre. The semiquinone radical is coordinatively labile and dissociates from the Cu(I) centre. The biological implications of these results are mentioned.
15

none

Huang, Chia-chi 07 July 2009 (has links)
none
16

Model studies of the cub-histidine-tyrosine centre in cytochrome c oxidase

Lee, Sang Tae, Chemistry, Faculty of Science, UNSW January 2005 (has links)
This thesis reports the synthesis and copper coordination chemistry of covalently-linked aryl-imidazole derivatives designed as models for the crosslinked imidazole-phenol sidechains of the His-Tyr cofactor in the CcO. Three new imidazole- (HL1 - HL3) and three new indole- (HL4 - H2L6) containing tripodal ligands were synthesised. The conjugate addition of an imidazole to activated quinone derivatives was developed as a new route to organic models for the Tyr His cofactor. Two monodentate imidazole-aryl, Im-hq(OH)2 and Im-ArOH, and an imidazole-quinone, Im bq were obtained using this route. The X-ray crystal structure of Im-hq(OH)2.EtOH was determined. The route was also used to give new chelating ligands, H2L10 and HL12, containing a cross-linked imidazole-phenol surrogate for the Tyr244-His240 cofactor. Copper complexes of Im-hq(OH)2, Im-bq, Im-ArOH, H2L10-HL12, and HL1-H2L6 were prepared, and the X-ray crystal structures of [Cu(terpy)(Im-bq)][BF4]2 and five other copper complexes were determined. The physiochemical properties of the copper complexes were characterized by FT-IR, UV-Vis-NIR, EPR and (spectro)electrochemical studies. Key results include: the oxidation of Im-ArO- anion affords the semiquinone radical, Im-sq(4OH)(1O??????), in a hydrous solvent. However, the oxidations of neutral Im-ArOH and [Cu(tpa)(Im-ArOH)]2+ produce the corresponding phenoxy radical species that rapidly and reversibly dimerise to give quinol cyclohexadienone, QCHD, dimers. Significantly [Cu(tpa)(Im-sq(4OH)(1O??????))]2+ was EPR silent, perhaps due to antiferromagnetic coupling between the Cu(II) (S=1/2) and semiquinonyl radical (S=1/2) centres. Deprotonation of the hydroquinone in [Cu(tpa)(Im-hq(OH)2]2+ produces the hydroquinone dianion which reduces the Cu(II) centre. The semiquinone radical is coordinatively labile and dissociates from the Cu(I) centre. The biological implications of these results are mentioned.
17

Incorporation of histidine-rich metal-binding sites onto small protein scaffolds implications for imaging, therapeutics, and catalysis /

Soebbing, Samantha Lynn. January 2008 (has links)
Thesis (Ph. D.)--University of Iowa, 2008. / Thesis supervisor: Sonya J. Franklin. Includes bibliographical references (leaves 129-134).
18

Der Einfluss trunkulärer Vagotomie auf die spezifische Histidindecarboxylase und auf Gastrin im Rattenmagen

Keller, Monika, January 1979 (has links)
Thesis (doctoral)--Ludwig Maximilians-Universität zu München, 1979.
19

The Role of Histidine-rich Glycoprotein in Coagulation & Fibrinolysis

MacQuarrie, Jessica 12 1900 (has links)
<p> The fibrinolytic system has an important role in maintaining vascular patency by restricting fibrin clot formation to prevent occlusion of the blood vessel. Plasminogen activation is the central event in fibrinolysis and is tightly regulated by activators and inhibitors. Histidine-rich glycoprotein (HRG) is an abundant plasma protein that has been proposed to have a regulatory role in many biological processes, including fibrinolysis. Approximately 50% ofplasminogen in the blood circulates in complex with HRG. Conflicting reports dispute the role of HRG in fibrinolysis, specifically whether it promotes or inhibits plasminogen activation. To elucidate the role of HRG in fibrinolysis, we isolated HRG from human plasma and analyzed its effect on plasminogen activation by tissue-type plasminogen activator in a kinetic assay. HRG had no significant effect on plasminogen activation by tissue-type plasminogen activator once contaminating plasminogen was eliminated from our HRG preparations. Based on these results, the focus of our research was redirected to analyzing the effect of HRG on additional plasminogen activators, namely urinary-type plasminogen activator and factor (F) Xlla. HRG inhibited plasminogen activation by both activators. HRG had the greatest inhibitory effect on FXIIa activity. This novel finding led us to explore the relationship between HRG and FX.IIa by measuring the affinity of HRG for FXIIa by surface plasmon resonance, and by analyzing the effect of HRG on FXIIa activity in various contact pathway reactions. ZnCh was also included in these reactions because it plays an important role in enhancing both HRG-and FXII-mediated interactions and is released by activated platelets. In the presence of 12.5 μM ZnCl2, FXIIa bound to the histidine-rich region of HRG with very high affinity (Kd = 56 ± 8.9 pM). Interestingly, HRG does not bind to FXII. Functional analysis of HRG revealed that it significantly inhibits a number of contact pathway reactions, including FXII autoactivation, kallikreinmediated FXII activation, and FXIIa-mediated FXI activation. Conversely, HRG enhanced FXIIa-mediated prekallikrein activation. Based on these findings, we hypothesize that HRG binds to an exosite on FXIIa, which is not expressed by the zymogen FXII, and alters FXIIa activity. The mechanism of HRG-mediated FXIIa inhibition is not fully understood and needs to be further analyzed by both binding and functional assays. These observations raise the possibility that the main function of HRG is to modulate FXIIa activity, rather than plasminogen activation. Because of its abundance, HRG may function as a modulator of haemostasis through its effect on coagulation and fibrinolysis. </p> / Thesis / Master of Science (MSc)
20

Structural and functional characterisation of PKCI

Kerai, Preeti January 1999 (has links)
No description available.

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